NAO VOLUME 3 QUESTIONS WITH 100%
CORRECT ANSWERS.
You are fitting a patient with a stock frame, 24 DBL, 44 eve size and 137 mm skull
temples. The distance PD is only 62 mm. If by some unfortunate error the lenses are
not decentered at all, how much prism is created in each eye?
RX: OU -2.25 -1.50 x 045 - CORRECT ANSWER-0.5 prism BI
A situation where the frame front is somewhat twisted, with the planes of the two lenses
being out of line with one another, is called: - CORRECT ANSWER-Skewed bridge
When a frame is said to have a parabolic curve (or positive face form), the following
condition is meant: - CORRECT ANSWER-The bridge of the frame is out further than
then end pieces
If the lenses of a patient wearing -8.00 spheres are brought closer or his/her eyes, what
if any effect will this have on the lenses? - CORRECT ANSWER-Increase minus power
effect
Moving the optical center of a plus lens inward from the correct PD results in _____ -
CORRECT ANSWER-Base in prism
Where will the optical center appear in a lensometer when neutralizing a left lens for
base in prism? - CORRECT ANSWER-To the left of the target center
Glazing is a term used to indicate _____ - CORRECT ANSWER-A defect that occurs
when an anti-reflective lens is tinted
Frequently, bicentric grinding (slab-off) is used as a means of obtaining prism in the
reading field to correct induced prism imbalance. The usual correction during the
fabrication process is achieved by grinding prism in the following direction: - CORRECT
ANSWER-up
A patient stops in to see you for adjustment of his glasses. After careful inspection you
find the only thing wrong that there is too much pantoscopic tilt. To make the necessary
adjustment you will: - CORRECT ANSWER-Angle the temples upward from the end
pieces
, The correct transposed RX for -1.00-.50x37 is? - CORRECT ANSWER--1.50 + 0.50 x
127
The correct transposition for +2.00 -2.00 x 060 is? - CORRECT ANSWER-Plano +2.00
x 150
An uncut lens must be at least _______ mm in diameter to allow the edging of a 54 mm
round lens decentered 3 mm in: - CORRECT ANSWER-60 mm
A +3.00 sphere lens has a front base curve of +6.25. What is the back surface curve? -
CORRECT ANSWER--3.25
A -2.00 -1.00 x 045 lens has a front base curve of +6.25. What are the back surface
curves? - CORRECT ANSWER--8.25 -1.00
If the RX is +2.00 -4.00 x 135, it would be necessary to decenter the lens _____to
create 1.00 prism base in : - CORRECT ANSWER-not possible
Rewrite the RX below, which is prescribed for a patient afflicted with double vision, so
as to make better balanced lenses:
OD -1.00 -0.50 x 090 5.00 BU
OS -1.25 - 0.50 x 090 1.00 BD - CORRECT ANSWER-OD -1.00 -0.50 x 090 3.00 prism
BU
OS -1.25 -0.50x 090 3.00 prism BD
Correct the imbalance in the following prescription by use of slab-off. Reading level is
10 mm:
OD +5.00 -2.00 x 090
OS +2.25 -3.00 x 090 - CORRECT ANSWER-2.25 prism BU in OS
Slab-off is ground on the lens that has the _____in the 090 meridian: - CORRECT
ANSWER-Weaker plus
Which of the following areas is not a factor in determining vertical imbalance? -
CORRECT ANSWER-Add power
A lens dispersing white light into its component colors is an example of : - CORRECT
ANSWER-Chromatic aberration
The lens aberration that produces a shorter focal length for rays near the edge of the
lens than rays near the optical axis is called: - CORRECT ANSWER-Spherical
aberration
CORRECT ANSWERS.
You are fitting a patient with a stock frame, 24 DBL, 44 eve size and 137 mm skull
temples. The distance PD is only 62 mm. If by some unfortunate error the lenses are
not decentered at all, how much prism is created in each eye?
RX: OU -2.25 -1.50 x 045 - CORRECT ANSWER-0.5 prism BI
A situation where the frame front is somewhat twisted, with the planes of the two lenses
being out of line with one another, is called: - CORRECT ANSWER-Skewed bridge
When a frame is said to have a parabolic curve (or positive face form), the following
condition is meant: - CORRECT ANSWER-The bridge of the frame is out further than
then end pieces
If the lenses of a patient wearing -8.00 spheres are brought closer or his/her eyes, what
if any effect will this have on the lenses? - CORRECT ANSWER-Increase minus power
effect
Moving the optical center of a plus lens inward from the correct PD results in _____ -
CORRECT ANSWER-Base in prism
Where will the optical center appear in a lensometer when neutralizing a left lens for
base in prism? - CORRECT ANSWER-To the left of the target center
Glazing is a term used to indicate _____ - CORRECT ANSWER-A defect that occurs
when an anti-reflective lens is tinted
Frequently, bicentric grinding (slab-off) is used as a means of obtaining prism in the
reading field to correct induced prism imbalance. The usual correction during the
fabrication process is achieved by grinding prism in the following direction: - CORRECT
ANSWER-up
A patient stops in to see you for adjustment of his glasses. After careful inspection you
find the only thing wrong that there is too much pantoscopic tilt. To make the necessary
adjustment you will: - CORRECT ANSWER-Angle the temples upward from the end
pieces
, The correct transposed RX for -1.00-.50x37 is? - CORRECT ANSWER--1.50 + 0.50 x
127
The correct transposition for +2.00 -2.00 x 060 is? - CORRECT ANSWER-Plano +2.00
x 150
An uncut lens must be at least _______ mm in diameter to allow the edging of a 54 mm
round lens decentered 3 mm in: - CORRECT ANSWER-60 mm
A +3.00 sphere lens has a front base curve of +6.25. What is the back surface curve? -
CORRECT ANSWER--3.25
A -2.00 -1.00 x 045 lens has a front base curve of +6.25. What are the back surface
curves? - CORRECT ANSWER--8.25 -1.00
If the RX is +2.00 -4.00 x 135, it would be necessary to decenter the lens _____to
create 1.00 prism base in : - CORRECT ANSWER-not possible
Rewrite the RX below, which is prescribed for a patient afflicted with double vision, so
as to make better balanced lenses:
OD -1.00 -0.50 x 090 5.00 BU
OS -1.25 - 0.50 x 090 1.00 BD - CORRECT ANSWER-OD -1.00 -0.50 x 090 3.00 prism
BU
OS -1.25 -0.50x 090 3.00 prism BD
Correct the imbalance in the following prescription by use of slab-off. Reading level is
10 mm:
OD +5.00 -2.00 x 090
OS +2.25 -3.00 x 090 - CORRECT ANSWER-2.25 prism BU in OS
Slab-off is ground on the lens that has the _____in the 090 meridian: - CORRECT
ANSWER-Weaker plus
Which of the following areas is not a factor in determining vertical imbalance? -
CORRECT ANSWER-Add power
A lens dispersing white light into its component colors is an example of : - CORRECT
ANSWER-Chromatic aberration
The lens aberration that produces a shorter focal length for rays near the edge of the
lens than rays near the optical axis is called: - CORRECT ANSWER-Spherical
aberration
